The immune modulating effect of blood transfusions which are beneficial in the renal transplant situation may be detrimental to patients undergoing surgery for malignancy. Pretransplant transfusion is associated with impaired delayed hypersensitivity responses and prolonged kidney graft survival. Impaired delayed hypersensitivity in preoperative cancer patients is associated with advanced disease and early recurrence following surgery. A retrospective study of colon cancer recurrence following perioperative blood transfusion indicates that transfusions are associated with early recurrence. The profound clinical significance of this finding demands prompt confirmation. We propose a prospective study of colon cancer recurrence following perioperative transfusion. In addition, because operated patients with malignancies will continue to require transfusions in preparation for surgery or in compensation for intraoperative blood loss, the effect of frozen blood on colon cancer recurrence will be evaluated in patients who require transfusion. Frozen blood does not cause HLA isosensitization when administered to dialysis patients and does not prolong kidney graft survival. Frozen blood, by not causing immune modulation in cancer patients, may not be associated with early recurrence. Recurrence following standard transfusion, transfusion of frozen blood, and no transfusion will be evaluated controlling for stage, timing, procedure, postoperative therapy, and anesthetic. The results of the study will evaluate the influence of perioperative transfusion on recurrence following colorectal surgery. The possible role of frozen blood in ameliorating the effect of transfusion on colon cancer recurrence will also be evaluated.